Device in paper and cardboard forming machines of the suction forming cylinder type



June 11, 1968 A. o. LITMA DEVICE IN PAPER AND CARDBOARD FORMING MACHINE THE sucnon FORMING CYLINDER TY Filed Sept. 10, 1965 IA/VE/VTOA ALlA/V OLAV/ L ITM/I United States Patent 3,388,040 DEVKIE IN PAPER AND CARDBOARD FORMING MACHKNES GE THE SUCTIQN FORMING CYL- ENDER TYPE Allan Olavi Litma, 10A Koivistontie, 12 Tampere, Finland Fiied Sept. 19, 1965, Ser. No. 486,416 6 Claims. (6i. 162329) ABSTRACT OF THE DISCLGSURE This invention relates to the flow channels of paper and cardboard forming machines of the suction forming cylinder type, through which channel the fiber suspension flows and is directed to the surface of the cylinder surface. In such machines in accordance with the invention, the front wall of the flow channel at the forming area comprises the surface of the suction cylinder while the rear wall comprises a movable plate-formed construction element, said rear wall being mounted movably along a guiding surface or surfaces parallel with a tangent of the suction cylinder passing through the outlet opening of the flow channel. The control element can consist of an automatically controlled device, such as a pneumatic element controlled by the variations of the flow rate as measured by pressure difference meters or the like situated in the pipework preceding the flow channel, so that the rear wall of the flow channel is moved to a position most suitable for the flow rate of suspension at each moment. This device is more particularly described in Finnish patent application No. 1,528/64 and in a corresponding US. patent application Ser. No. 486,450.

The object of the device is to permit adjustment of the flow across section area of the flow channel sealed against the rising half of the cylinder so that the flow velocity of the suspension as it contacts the cylinder surface and flows further in the forming area of the channel will be the most suitable for the flow rate determined according to paper or cardboard production techniques.

Prior known is a construction, where adjustment of the flow cross section area is provided by aseparate body, one wall of which constitutes a rear wall for the flow channel while another wall is provided by the cylinder surface. Said body is mounted for adjustment separately in a horizontal plane and a vertical plane and for being inclined, while the excess fiber suspension which does not adhere to the cylinder surface flows through a flow port over the rear wall to the inside of said body to be led further to waste or to be recycled (see US. Patent No. 2,781,700). This design, however, does not provide the flow cross section area in the suction cylinder forming area of the flow channel which is most suitable technically at all fiber suspension flow rates, the favourable area of adjustment being fairly restricted.

The invention is more fully described in the following with reference to the accompanying drawing in which a device according to the invention is shown as an example in cross section.

In the drawing a suction forming cylinder is shown at 1 rotating in the direction of the arrow. The outlet end of the pipework preceding the suspension flow channel 3 is shown at 2 provided with a perforated roll 4. The rear wall of the flow channel 3 consists of an arcuate plate 5 with a curvature radius somewhat greater than the radius of cylinder 1. At its lower portion the plate 5 diverges from the cylinder, and its extension 6 which is straight forms an approximately right angle with a radius of the cylinder passing through the outlet opening 7 of flow channel 3, in other words the extension 6 is approximately parallel with a tangent of cylinder 1 passing through the 3,388,040 Patented June 11, 1968 outlet opening 7 of flow channel 3. To the machine body 8 is fitted a guide element 9, parallel with extension 6 and provided with a gasket 10. The extension 6 is at its lower end attached to control element 11, by means of which it is possible to move the extension 6 and the rear wall of 5 of flow channel 3 in the direction of said tangent to suit the momentary suspension flow rate.

Said control of the rear wall can be made automatic by simple means, in which case the eventual variations of the suspension flow rate automatically cause a corresponding movement of the rear wall 6 of flow channel 3, and thus the most favourable flow condition will be maintained at the forming area. The automatic devices are not shown in the drawing, since they are per se known to experts in the art, although not previously utilized in the said application.

When moving the rear wall 5 either by hand or automatically it may be necessary to be able to vary the size of the flow channel outlet opening in accordance with the proper flow conditions. To provide this adjustment possibility, an car 12 is attached near the outlet opening 7 of plate 5 adjacent each edge of the plate. At the free end of ear 12 there is a pin 13 extending into an oblong guiding groove 14 in element 15, which in turn is piv-otally mounted in body 16. The location of said mounting can preferably be movable e.g. horizontally and vertically in a manner known per se.

Position adjustment of groove 14 can be provided e.g. in the manner shown in the construction example according to the drawing, by means of'a joined crank device, in which case a rod 18 at its one end is mounted in an ear 17 attached to element 15, the other end of the rod 18 being mounted in an car 19 which in turn is attached to a shaft 20 rotatable by means of a work gear (not shown) and at its ends supported on body 16.

When the longitudinal axis of groove 14 is placed in a position that deviates from the direction of guide element 9, and when rear plate 5 is moved either automatically or by hand, the size of the outlet opening 7 of flow channel 3 will increase or decrease, depending upon the direction in which the axis of groove 14 deviates from the direction of guide elements 9.

The invention is not limited to the construction described above and illustrated in the drawing but can be modified in many ways constructionally inside the scope of the invention as defined in the accompanying claims.

What I claim is:

1. Apparatus in cardboard and paper forming machines of the suction forming cylinder type and having a fiber suspension flow channel including a front wall formed by the surface of the suction forming cylinder of the machine and a rear wall formed by an arcuate plate extending along and spaced from said front wall and mounted for movement towards and away therefrom, said plate forming an outlet opening for the fiow channel adjacent an edge of the plate, comprising means connected to said rear wall operable to shift the rear wall towards and away from the front wall, and adjustable means connected to the rear wall near said outlet opening adapted to be selectively adjusted automatically to maintain, decrease or increase the size of said outlet opening when the rear wall is moved towards and away from the front wall.

2. Apparatus as claimed in claim 1, in which said adjustable means comprises an element rotatably mounted on a support in a plane substantially normal to the rear wall, said element having a slot therein, a pin connected to the rear wall and slidably fitting in said slot, and means connected to the element to rotate the latter to change the angle of the slot relative to the rear wall.

3. Apparatus as claimed in claim 2, in which said means for rotating the element includes a shaft rotatably mounted on said support near said element, a first lug connected to the element and extending outwardly therefrom, a second 111g connected to the shaft extending radially substantially parallel to the first lug, and a link extending between and pivotally connected to said first and second lugs.

4. Apparatus as claimed in claim 1, including guide sur face means extending approximately parallel with a tangent of said cylinder passing through the outlet opening, said rear Wall being mounted to move along the guide surface means when the rear wall is moved towards and away from the front wall.

5. Apparatus as claimed in claim 4, in which said adjustable means comprises an element rotatably mounted on a support in a plane substantially normal to the rear wall, said element having a slot therein extending substantially parallel to said guide surface means, a pin connected to the rear wall and slidably fitting in said slot, and means 4 a connected to the element to rotate the latter to change the angle of the slot relative to the rear wall.

'6. Apparatus as claimed in claim 5, in which said means for rotating the element includes a shaft rotatably mounted on said support near said element, a first lug connected to the element and extending outwardly therefrom, a second lug connected to the shaft extending radially substantially parallel to the first lug, and a link extending between and pivotally connected to said first and second lugs.

References Cited UNITED STATES PATENTS 2,509,296 5/1950 Goldsmith 162329 DONALL H. SYLVESTER, Primary Examiner. ALBERT C. HODGSON, Examiner. 

